docs: def _load_folder(folder_entry, corpus):
          """ Load the given subfolder into the corpus (e.g. bed, one, ...) """
          for wav_path in glob.glob(os.path.join(folder_entry.path, '*.wav')):
              wav_name = os.path.basename(wav_path)
              basename, __ = os.path.splitext(wav_name)
  
              command = folder_entry.name
              file_idx = '{}_{}'.format(basename, command)
              issuer_idx = str(basename).split('_', maxsplit=1)[0]
  
              corpus.new_file(wav_path, file_idx)
  
              if issuer_idx not in corpus.issuers.keys():
                  corpus.import_issuers(issuers.Speaker(
                      issuer_idx
                  ))
  
              utt = corpus.new_utterance(file_idx, file_idx, issuer_idx)
  
              labels = annotations.LabelList.create_single(command, idx=audiomate.corpus.LL_WORD_TRANSCRIPT)
              utt.set_label_list(labels)